drivers/of/of_reserved_mem.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Device tree based initialization code for reserved memory.
   4  *
   5  * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
   6  * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
   7  *              http://www.samsung.com
   8  * Author: Marek Szyprowski <m.szyprowski@samsung.com>
   9  * Author: Josh Cartwright <joshc@codeaurora.org>
  10  */
  11
  12 #define pr_fmt(fmt)     "OF: reserved mem: " fmt
  13
  14 #include <linux/err.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/mm.h>
  19 #include <linux/sizes.h>
  20 #include <linux/of_reserved_mem.h>
  21 #include <linux/sort.h>
  22 #include <linux/slab.h>
  23 #include <linux/memblock.h>
  24 #include <linux/kmemleak.h>
  25
  26 #include "of_private.h"
  27
  28 #define MAX_RESERVED_REGIONS    64
  29 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
  30 static int reserved_mem_count;
  31
  32 static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
  33         phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
  34         phys_addr_t *res_base)
  35 {
  36         phys_addr_t base;
  37         int err = 0;
  38
  39         end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
  40         align = !align ? SMP_CACHE_BYTES : align;
  41         base = memblock_phys_alloc_range(size, align, start, end);
  42         if (!base)
  43                 return -ENOMEM;
  44
  45         *res_base = base;
  46         if (nomap) {
  47                 err = memblock_mark_nomap(base, size);
  48                 if (err)
  49                         memblock_free(base, size);
  50                 kmemleak_ignore_phys(base);
  51         }
  52
  53         return err;
  54 }
  55
  56 /*
  57  * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
  58  */
  59 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
  60                                       phys_addr_t base, phys_addr_t size)
  61 {
  62         struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
  63
  64         if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
  65                 pr_err("not enough space for all defined regions.\n");
  66                 return;
  67         }
  68
  69         rmem->fdt_node = node;
  70         rmem->name = uname;
  71         rmem->base = base;
  72         rmem->size = size;
  73
  74         reserved_mem_count++;
  75         return;
  76 }
  77
  78 /*
  79  * __reserved_mem_alloc_size() - allocate reserved memory described by
  80  *      'size', 'alignment'  and 'alloc-ranges' properties.
  81  */
  82 static int __init __reserved_mem_alloc_size(unsigned long node,
  83         const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
  84 {
  85         int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
  86         phys_addr_t start = 0, end = 0;
  87         phys_addr_t base = 0, align = 0, size;
  88         int len;
  89         const __be32 *prop;
  90         bool nomap;
  91         int ret;
  92
  93         prop = of_get_flat_dt_prop(node, "size", &len);
  94         if (!prop)
  95                 return -EINVAL;
  96
  97         if (len != dt_root_size_cells * sizeof(__be32)) {
  98                 pr_err("invalid size property in '%s' node.\n", uname);
  99                 return -EINVAL;
 100         }
 101         size = dt_mem_next_cell(dt_root_size_cells, &prop);
 102
 103         prop = of_get_flat_dt_prop(node, "alignment", &len);
 104         if (prop) {
 105                 if (len != dt_root_addr_cells * sizeof(__be32)) {
 106                         pr_err("invalid alignment property in '%s' node.\n",
 107                                 uname);
 108                         return -EINVAL;
 109                 }
 110                 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
 111         }
 112
 113         nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 114
 115         /* Need adjust the alignment to satisfy the CMA requirement */
 116         if (IS_ENABLED(CONFIG_CMA)
 117             && of_flat_dt_is_compatible(node, "shared-dma-pool")
 118             && of_get_flat_dt_prop(node, "reusable", NULL)
 119             && !nomap) {
 120                 unsigned long order =
 121                         max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
 122
 123                 align = max(align, (phys_addr_t)PAGE_SIZE << order);
 124         }
 125
 126         prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 127         if (prop) {
 128
 129                 if (len % t_len != 0) {
 130                         pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
 131                                uname);
 132                         return -EINVAL;
 133                 }
 134
 135                 base = 0;
 136
 137                 while (len > 0) {
 138                         start = dt_mem_next_cell(dt_root_addr_cells, &prop);
 139                         end = start + dt_mem_next_cell(dt_root_size_cells,
 140                                                        &prop);
 141
 142                         ret = early_init_dt_alloc_reserved_memory_arch(size,
 143                                         align, start, end, nomap, &base);
 144                         if (ret == 0) {
 145                                 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 146                                         uname, &base,
 147                                         (unsigned long)(size / SZ_1M));
 148                                 break;
 149                         }
 150                         len -= t_len;
 151                 }
 152
 153         } else {
 154                 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
 155                                                         0, 0, nomap, &base);
 156                 if (ret == 0)
 157                         pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
 158                                 uname, &base, (unsigned long)(size / SZ_1M));
 159         }
 160
 161         if (base == 0) {
 162                 pr_info("failed to allocate memory for node '%s'\n", uname);
 163                 return -ENOMEM;
 164         }
 165
 166         *res_base = base;
 167         *res_size = size;
 168
 169         return 0;
 170 }
 171
 172 static const struct of_device_id __rmem_of_table_sentinel
 173         __used __section("__reservedmem_of_table_end");
 174
 175 /*
 176  * __reserved_mem_init_node() - call region specific reserved memory init code
 177  */
 178 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
 179 {
 180         extern const struct of_device_id __reservedmem_of_table[];
 181         const struct of_device_id *i;
 182         int ret = -ENOENT;
 183
 184         for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
 185                 reservedmem_of_init_fn initfn = i->data;
 186                 const char *compat = i->compatible;
 187
 188                 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
 189                         continue;
 190
 191                 ret = initfn(rmem);
 192                 if (ret == 0) {
 193                         pr_info("initialized node %s, compatible id %s\n",
 194                                 rmem->name, compat);
 195                         break;
 196                 }
 197         }
 198         return ret;
 199 }
 200
 201 static int __init __rmem_cmp(const void *a, const void *b)
 202 {
 203         const struct reserved_mem *ra = a, *rb = b;
 204
 205         if (ra->base < rb->base)
 206                 return -1;
 207
 208         if (ra->base > rb->base)
 209                 return 1;
 210
 211         /*
 212          * Put the dynamic allocations (address == 0, size == 0) before static
 213          * allocations at address 0x0 so that overlap detection works
 214          * correctly.
 215          */
 216         if (ra->size < rb->size)
 217                 return -1;
 218         if (ra->size > rb->size)
 219                 return 1;
 220
 221         return 0;
 222 }
 223
 224 static void __init __rmem_check_for_overlap(void)
 225 {
 226         int i;
 227
 228         if (reserved_mem_count < 2)
 229                 return;
 230
 231         sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
 232              __rmem_cmp, NULL);
 233         for (i = 0; i < reserved_mem_count - 1; i++) {
 234                 struct reserved_mem *this, *next;
 235
 236                 this = &reserved_mem[i];
 237                 next = &reserved_mem[i + 1];
 238
 239                 if (this->base + this->size > next->base) {
 240                         phys_addr_t this_end, next_end;
 241
 242                         this_end = this->base + this->size;
 243                         next_end = next->base + next->size;
 244                         pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
 245                                this->name, &this->base, &this_end,
 246                                next->name, &next->base, &next_end);
 247                 }
 248         }
 249 }
 250
 251 /**
 252  * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
 253  */
 254 void __init fdt_init_reserved_mem(void)
 255 {
 256         int i;
 257
 258         /* check for overlapping reserved regions */
 259         __rmem_check_for_overlap();
 260
 261         for (i = 0; i < reserved_mem_count; i++) {
 262                 struct reserved_mem *rmem = &reserved_mem[i];
 263                 unsigned long node = rmem->fdt_node;
 264                 int len;
 265                 const __be32 *prop;
 266                 int err = 0;
 267                 bool nomap;
 268
 269                 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
 270                 prop = of_get_flat_dt_prop(node, "phandle", &len);
 271                 if (!prop)
 272                         prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
 273                 if (prop)
 274                         rmem->phandle = of_read_number(prop, len/4);
 275
 276                 if (rmem->size == 0)
 277                         err = __reserved_mem_alloc_size(node, rmem->name,
 278                                                  &rmem->base, &rmem->size);
 279                 if (err == 0) {
 280                         err = __reserved_mem_init_node(rmem);
 281                         if (err != 0 && err != -ENOENT) {
 282                                 pr_info("node %s compatible matching fail\n",
 283                                         rmem->name);
 284                                 if (nomap)
 285                                         memblock_clear_nomap(rmem->base, rmem->size);
 286                                 else
 287                                         memblock_free(rmem->base, rmem->size);
 288                         }
 289                 }
 290         }
 291 }
 292
 293 static inline struct reserved_mem *__find_rmem(struct device_node *node)
 294 {
 295         unsigned int i;
 296
 297         if (!node->phandle)
 298                 return NULL;
 299
 300         for (i = 0; i < reserved_mem_count; i++)
 301                 if (reserved_mem[i].phandle == node->phandle)
 302                         return &reserved_mem[i];
 303         return NULL;
 304 }
 305
 306 struct rmem_assigned_device {
 307         struct device *dev;
 308         struct reserved_mem *rmem;
 309         struct list_head list;
 310 };
 311
 312 static LIST_HEAD(of_rmem_assigned_device_list);
 313 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
 314
 315 /**
 316  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
 317  *                                        given device
 318  * @dev:        Pointer to the device to configure
 319  * @np:         Pointer to the device_node with 'reserved-memory' property
 320  * @idx:        Index of selected region
 321  *
 322  * This function assigns respective DMA-mapping operations based on reserved
 323  * memory region specified by 'memory-region' property in @np node to the @dev
 324  * device. When driver needs to use more than one reserved memory region, it
 325  * should allocate child devices and initialize regions by name for each of
 326  * child device.
 327  *
 328  * Returns error code or zero on success.
 329  */
 330 int of_reserved_mem_device_init_by_idx(struct device *dev,
 331                                        struct device_node *np, int idx)
 332 {
 333         struct rmem_assigned_device *rd;
 334         struct device_node *target;
 335         struct reserved_mem *rmem;
 336         int ret;
 337
 338         if (!np || !dev)
 339                 return -EINVAL;
 340
 341         target = of_parse_phandle(np, "memory-region", idx);
 342         if (!target)
 343                 return -ENODEV;
 344
 345         if (!of_device_is_available(target)) {
 346                 of_node_put(target);
 347                 return 0;
 348         }
 349
 350         rmem = __find_rmem(target);
 351         of_node_put(target);
 352
 353         if (!rmem || !rmem->ops || !rmem->ops->device_init)
 354                 return -EINVAL;
 355
 356         rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
 357         if (!rd)
 358                 return -ENOMEM;
 359
 360         ret = rmem->ops->device_init(rmem, dev);
 361         if (ret == 0) {
 362                 rd->dev = dev;
 363                 rd->rmem = rmem;
 364
 365                 mutex_lock(&of_rmem_assigned_device_mutex);
 366                 list_add(&rd->list, &of_rmem_assigned_device_list);
 367                 mutex_unlock(&of_rmem_assigned_device_mutex);
 368
 369                 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
 370         } else {
 371                 kfree(rd);
 372         }
 373
 374         return ret;
 375 }
 376 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 377
 378 /**
 379  * of_reserved_mem_device_init_by_name() - assign named reserved memory region
 380  *                                         to given device
 381  * @dev: pointer to the device to configure
 382  * @np: pointer to the device node with 'memory-region' property
 383  * @name: name of the selected memory region
 384  *
 385  * Returns: 0 on success or a negative error-code on failure.
 386  */
 387 int of_reserved_mem_device_init_by_name(struct device *dev,
 388                                         struct device_node *np,
 389                                         const char *name)
 390 {
 391         int idx = of_property_match_string(np, "memory-region-names", name);
 392
 393         return of_reserved_mem_device_init_by_idx(dev, np, idx);
 394 }
 395 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
 396
 397 /**
 398  * of_reserved_mem_device_release() - release reserved memory device structures
 399  * @dev:        Pointer to the device to deconfigure
 400  *
 401  * This function releases structures allocated for memory region handling for
 402  * the given device.
 403  */
 404 void of_reserved_mem_device_release(struct device *dev)
 405 {
 406         struct rmem_assigned_device *rd, *tmp;
 407         LIST_HEAD(release_list);
 408
 409         mutex_lock(&of_rmem_assigned_device_mutex);
 410         list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
 411                 if (rd->dev == dev)
 412                         list_move_tail(&rd->list, &release_list);
 413         }
 414         mutex_unlock(&of_rmem_assigned_device_mutex);
 415
 416         list_for_each_entry_safe(rd, tmp, &release_list, list) {
 417                 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
 418                         rd->rmem->ops->device_release(rd->rmem, dev);
 419
 420                 kfree(rd);
 421         }
 422 }
 423 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
 424
 425 /**
 426  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
 427  * @np:         node pointer of the desired reserved-memory region
 428  *
 429  * This function allows drivers to acquire a reference to the reserved_mem
 430  * struct based on a device node handle.
 431  *
 432  * Returns a reserved_mem reference, or NULL on error.
 433  */
 434 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
 435 {
 436         const char *name;
 437         int i;
 438
 439         if (!np->full_name)
 440                 return NULL;
 441
 442         name = kbasename(np->full_name);
 443         for (i = 0; i < reserved_mem_count; i++)
 444                 if (!strcmp(reserved_mem[i].name, name))
 445                         return &reserved_mem[i];
 446
 447         return NULL;
 448 }
 449 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);